History
Risks to Forests
Symptoms and Identification
   On Oak & Tanoak
   On Other Hosts
How P. ramorum is spread
Regulated Hosts

Introduction (continued)

Symptoms and ID on Oak and Tanoak

Phytophthora ramorum causes two types of diseases, depending on the host. On members of the oak family (Fagaceae), it causes stem cankers that kill the host; hence the name “sudden oak death.”  These cankers often show the characteristic “bleeding” symptom, such as in the photos below and at right.

Bleeding on tanoak caused by Phytophthora ramorum. Photo by J. Parke.

It is important to note that not all oak species are affected by Phytophthora ramorum. Oregon white oak (Quercus garryanna) has not become infected by this pathogen.

<< Previous

Next >>